Gilberts revives natural ventilation for NHM

05 September, 2017

While the famous ‘Dippy’ the diplodocus dinosaur exhibit in the Hintze Hall of the Natural History Museum in London was being replaced with a real skeleton of a blue whale, the opportunity was taken to revive, as far as possible, the original ventilation for this iconic, lofty hall. The project in the 150-year-old Grade I listed hall saw consulting engineers SVM utilising the experience of air-movement specialist Gilberts.

With the help of CFD (computational fluid dynamics) modelling, Gilberts produced 24 bespoke units of its Mistrale Model A natural-ventilation units, with a further 42 standard WHF50 high-performance louvres to provide the required levels of fresh and exhaust air.

Each bespoke unit was purpose-designed using a combination of Gilberts’ WHF50 cassette with the VN75 ultra-low-leakage air-volume control damper to fit within existing window apertures and frames, and bolt together into specially designed subframes to avoid any need to fix into the existing terracotta surrounds.

These units were required to provide the appropriate flow of fresh air into the hall without allowing any daylight to pass through and still look aesthetically pleasing. A bespoke combination of Internal K40 fixed-bar grilles and non-vision cores mounted on the rear of the units provided the solution.

In a separate high-level atrium, the glazing was removed from the window frames and replaced with WHF50 louvres to provide high-level discharge of exhaust air.

SVM director Paul Rushmer elaborated, ‘The project involved refurbishing the existing hall and redesigning the space to incorporate additional galleries at ground, first and second floor levels. From the original design, natural-ventilation openings were in place, to an extent, but needed restoring, and new building services had to be integrated alongside to deliver a balanced internal temperature all year round, regardless of summer peaks and winter lows.

‘Conditions in Hintze Hall are crucial to the exhibits, and of course important to the visitors. We had to find a non-invasive solution for the historic space, which stabilised the temperature and humidity. The original building drawings used passive solutions. We have past experience of working with Gilberts, and felt its dampers were particularly appropriate to helping develop a bespoke, sympathetic solution.’